Recent examples of -ketoglutarate-dependent mononuclear non-haem iron enzymes in natural product biosyntheses

Covering: up to 2018-Ketoglutarate (KG, also known as 2-oxoglutarate)-dependent mononuclear non-haem iron (KG-NHFe) enzymes catalyze a wide range of biochemical reactions, including hydroxylation, ring fragmentation, C-C bond cleavage, epimerization, desaturation, endoperoxidation and heterocycle formation. These enzymes utilize iron(ii) as the metallo-cofactor and KG as the co-substrate. Herein, we summarize several novel KG-NHFe enzymes involved in natural product biosyntheses discovered in recent years, including halogenation reactions, amino acid modifications and tailoring reactions in the biosynthesis of terpenes, lipids, fatty acids and phosphonates. We also conducted a survey of the currently available structures of KG-NHFe enzymes, in which KG binds to the metallo-centre bidentately through either a proximal- or distal-type binding mode. Future structure-function and structure-reactivity relationship investigations will provide crucial information regarding how activities in this large class of enzymes have been fine-tuned in nature.